Are individual differences in appetitive and defensive motivation related? A psychophysiological examination in two samples

Abstract

Appetitive and defensive motivation account for a good deal of variance in personality and mental health, but whether individual differences in these systems are correlated or orthogonal has not been conclusively established. Previous investigations have generally relied on self-report and have yielded conflicting results. We therefore assessed the relation between psychophysiological indices of appetitive and defensive motivation during elicitation of these motivational states: specifically, frontal electroencephalogram asymmetry during reward anticipation and startle response during anticipation of predictable or unpredictable threat of shock. Results in a sample of psychopathology-free community members (n=63), an independent sample of undergraduates with a range of internalising symptoms (n=64), and the combination of these samples (n=127) revealed that differences in responding to the two tasks were not significantly correlated. Average coefficients approached zero in all three samples (community: .04, undergraduate: −.01, combined: .06). Implications of these findings for research on normal and abnormal personality are discussed.

Keywords:

• Appetitive
• Defensive
• Positive affect
• Negative affect
• Psychophysiology

This research was supported by National Institute of Mental Health (NIMH) grants [T32 MH067631 (C.S.)], [R21 MH080689 (S.A.S)], [R01 MH098093 (S.A.S)], and [K08 MH083888 (J.R.B.)]; a UIC Chancellor's Discovery grant (S.A.S. and J.R.B.).

This research was supported by National Institute of Mental Health (NIMH) grants [T32 MH067631 (C.S.)], [R21 MH080689 (S.A.S)], [R01 MH098093 (S.A.S)], and [K08 MH083888 (J.R.B.)]; a UIC Chancellor's Discovery grant (S.A.S. and J.R.B.).

Notes

¹ There were also 12 loss trials during which participants lost money if the reels landed on three pieces of fruit (data not presented). The reason for these trials was that pilot testing on the task suggested that the task was uninteresting if there were only no-incentive and reward trials, and interspersing loss trials during the game made the reward trials feel ‘more exciting’.

² It should be noted that examining the relationship between appetitive and defensive motivation was not the primary aim of Jackson et al.'s study. They did report negative correlations of asymmetry at FP1/FP2 and FC3/FC4 with startle magnitude after picture offset, which they interpret as implicating prefrontal cortical involvement in automatic emotion regulation.

³ Furthermore, the finding in Study Two that internalising symptoms moderated EEG response to the slot machine task replicates that of Shankman et al. (2007), who found that early-onset depression moderated the effect of this task.